/ip dhcp-server alert

/tool e-mail send to=sample@example.com subject="TEST" body=[/log get value-name=message \
number=[/log print where topics=dhcp,critical,error]] from=alert@example.com

 /ip dhcp-server alert add on-alert=

/system logging action add email-to=

[admin@MikroTik] /system logging action> print
Flags: * - default
 #   NAME             TARGET REMOTE
 0 * memory           memory
 1 * disk             disk
 2 * echo             echo
 3 * remote           remote
 4   1                remote
 5   2                remote